Ultrasound imaging, also called ultrasound scanning or sonography, involves exposing part of the body to high-frequency sound waves to produce pictures of the inside of the body. Ultrasound exams do not use ionizing radiation (x-ray). Because ultrasound images
are captured in real-time, they can show the structure and movement of the body's internal organs, as well as blood flowing through blood vessels.

Ultrasound imaging is usually a painless medical test that helps physicians diagnose and treat medical conditions. Conventional ultrasound displays the images in thin, flat sections of the body. Advancements in ultrasound technology include three-dimensional
(3-D) ultrasound that formats the sound wave data into 3-D images. Four-dimensional (4-D) ultrasound is 3-D ultrasound in motion.

A Doppler ultrasound study may be part of an ultrasound examination. Doppler ultrasound is a special ultrasound technique that evaluates blood as it flows through a blood vessel, including the body's major arteries and veins in the abdomen, arms, legs and
neck.

There are three types of Doppler ultrasound:

Color Doppler uses a computer to convert Doppler measurements into an array of colors to visualize the speed and direction of blood flow through a blood vessel.

Power Doppler is a newer technique that is more sensitive than color Doppler and capable of providing greater detail of blood flow, especially in vessels that are located inside organs. Power Doppler, however, does not help the radiologist determine the direction
of flow, which may be important in some situations.

Ultrasound examinations can help to diagnose a variety of conditions and to assess organ damage following illness.

Ultrasound is used to help physicians diagnose symptoms such as pain, swelling, and infection.

Ultrasound is a useful way of examining many of the body's internal organs, including but not limited to the:

heart and blood vessels, including the abdominal aorta and its major branches

liver

gallbladder

spleen

pancreas

kidneys

bladder

uterus, ovaries, and unborn child (fetus) in pregnant patients

eyes

thyroid and parathyroid glands

scrotum (testicles)

Ultrasound is also used to:

guide procedures such as needle biopsies, in which needles are used to extract sample cells from an abnormal area for laboratory testing

image the breasts and to guide biopsy of breast cancer (see the Ultrasound-Guided Breast Biopsy page)

diagnose a variety of heart conditions and to assess damage after a heart attack or other illness

Doppler ultrasound images can help the physician to see and evaluate:

blockages to blood flow (such as clots)

narrowing of vessels (which may be caused by plaque)

tumors and congenital malformation

With knowledge about the speed and volume of blood flow gained from a Doppler ultrasound image, the physician can often determine whether a patient is a good candidate for a procedure like angioplasty.

The part of the patient to be X-rayed is placed between the X-ray source and the photographic receptor to produce what is a shadow of all the internal structure of that particular part of the body being X-rayed. The X-rays are blocked by dense tissues such
as bone and pass through soft tissues. Those areas where the X-rays strike the photographic receptor turn black when it is developed. So where the X-rays pass through "soft" parts of the body such as organs, muscle, and skin, the plate or film turns black.